Greg Rosalsky Planet Money Paper Round-Up KIRILL KUDRYAVTSEV/AFP via Getty Images hide caption Economists are constantly churning out fascinating research, and as much as we try at Planet Money, there's a lot of stuff we don't cover. So, periodically, we like to do a little round-up of interesting economic papers we've come across and share it with you in the Planet Money newsletter. (If you're not already subscribed, you can subscribe here). Welcome to the latest Planet Money Econ Paper Roundup! Recently, Jack Dorsey, the co-founder and CEO of Block (and co-founder and former CEO of Twitter), announced that he was laying off 4,000 workers — or about 40% of Block's workforce. And he suggested a big reason for the layoffs was AI had made many of the workers redundant. Block's stock price surged on the news. For what it's worth, analysts are skeptical that AI is the real reason Block is laying off so many workers.…